Excell formula to find the sum of all cells in column X from a vlookup in column y?

For what you want to do I would suggest a PIVOTTABLE.

This will be more useful as it can be sorted alphabetically, grouped by dates, etc etc.

To add a pivot table, select a cell in your data, choose the INSERT tab and The first icon should be PIVOTTABLE.

There are many guides on Pivot Tables on the web such as this...
http://www.experts-exchange.com/VP_1.html
Go to course progress, pivottables for the relevant PivotTable stuff.

(no points) Pivot table is definitely the way to go.. I was going to suggest an array formula if you're just looking at one user but a pivot would show you everyone as well as giving you the ability to

if one of the user's is say "john" then you're array formula would be
assuming Col A is username and Col B is the number of print jobs

=SUM(IF(A1:A2000="john",B1:B2000,0))

but you need to press CTRL + SHIFT + ENTER after to finish entering the formula

if you've done that right you'll see curly braces

{=SUM(IF(A1:A2000="john",B1:B2000,0))}

Rob, ditch the array formula in Excel 2010 for SUMIFS or simply SUMIF for all versions... no benifit from an array formula there.

=SUMIF(A1:A2000,"john",B1:B2000)

=SUMIFS(B1:B2000, A1:A2000,"john")

Good point Steve, thanks for the heads up :)

And so we get back to my initial solution... :)

Thanks DanCraciun and everyone else for their valuble input.

I was making a simple task a lot harded than It needed to be because of a lack of knowledge of what Excel can do. Thanks again for the simple and clear answer and explanation.